1. Field of the Invention
This invention relates generally to a dental apparatus for assisting dentists and technicians working with cast dental models for constructing prosthetic denture elements outside the patient's mouth. More particularly, this invention relates to an improved articulator which provides for flexible adjustability, convenient use and mass-production.
2. Description of the Prior Art
It is important that articulators used for supporting impressions of human jaws with artificial teeth including a lower jaw model and an upper jaw model, be capable of simulating the full range of occlusal and masticatory registrations among the patient population. The lower jaw model and the upper jaw model are supported by the articulator to be positioned in a contiguous relationship to provide centric, lateral and protrusive movement relative to each other and to simulate a patient's bite. While there are a wide variety of shapes, sizes and arrangements of human jaws and teeth, configurations and occlusion patterns have a broad range among different patients. Nevertheless, the process of making a jaw impression and the fabrication of partial dentures, fixed bridges and crowns by using jaw models in a dental laboratory requires that precise registration and desired occlusal alignment be maintained. Therefore, in order to satisfy this full range registration requirement, it often requires use of articulators which are complex, difficult to operate and expensive.
An articulator which has a wide range of registration and is simple to use, has been disclosed by Callne in U.S. Pat. No. 5,076,786, entitled "Cast Dental Articulator System and Method", issued on Dec. 31, 1991 wherein an articulator comprising two U-shaped wire frames is disclosed. These two frames are joined by hinges and springs. The frames may be snapped onto plastic clips cemented to the dental casts whereby the dental casts may be easily removed and reattached to the articulator in a highly repeatable manner. A slip-joint also provides the flexibility for left and right height adjustment to fit a wide range of dental cast models. The slip-joint further allows the upper wire frame to be completely separated from the lower wire frame.
While the articulator as disclosed in the aforementioned Callne Patent has a wide range of registration and is simple to use, it is desirable to provide an articulator structure with greater adjustment flexibility which is also renderable to being manufactured of light weight materials.